uiqoo
Member
[a,b] = a b a' b' = commutator
[a:b] = a b a' = conjugate (a = setup move)
In group theory, we use the word 'commutator' for (a b a' b') or (a' b' a b), and the sign '[a,b]' is also used.
However, we use 'b^a' for (a b a') or (a' b a) and we call (a b a') a conjugate of b by a. The sign '[a:b]' is not used.
∀g,h∈G, if ∃a such that a g a' = h, g and h are called to be a conjugate of each other.
And every h that is conjugate to g forms a conjugacy class Cl(g). (∀g,h∈Cl(g), ∃a s.t. a g a' = h)
A good example of a conjugacy class is {every corner 3-cycle}.
But, here's the point.
When we form a commuatator [a,b] = a b a' b', we can say a and b are in some kind of relationship.
For example, if [a,b]=I then we call a and b commutate to each other.
However when we form a conjugate [a:b] = a b a', we do NOT call that a and b are in conjugate. a and b are not in any relationship.
When c := [a:b], b and c are a conjugate of each other, not a and b. This is not intuitive at all.
Also the word 'commutator' and 'conjugate' is in different word class. (conjugator seems better?)
To be clear, in group theory, [a,b] is called a commuatator of a and b. And, a and b form some kind of relationship.
But [a:b], which is b^a, is NOT called a conjugate of a and b. It is called a conjugate of b by a. And, a and b do NOT form some kind of relationship.
So if we want to call [a:b] something, we need a term for this: [a,b] is called a (_________) of a and b.
The problem is the terms 'commutator' and 'conjugator' are not symmetric.
Any suggestions?
[a:b] = a b a' = conjugate (a = setup move)
In group theory, we use the word 'commutator' for (a b a' b') or (a' b' a b), and the sign '[a,b]' is also used.
However, we use 'b^a' for (a b a') or (a' b a) and we call (a b a') a conjugate of b by a. The sign '[a:b]' is not used.
∀g,h∈G, if ∃a such that a g a' = h, g and h are called to be a conjugate of each other.
And every h that is conjugate to g forms a conjugacy class Cl(g). (∀g,h∈Cl(g), ∃a s.t. a g a' = h)
A good example of a conjugacy class is {every corner 3-cycle}.
But, here's the point.
When we form a commuatator [a,b] = a b a' b', we can say a and b are in some kind of relationship.
For example, if [a,b]=I then we call a and b commutate to each other.
However when we form a conjugate [a:b] = a b a', we do NOT call that a and b are in conjugate. a and b are not in any relationship.
When c := [a:b], b and c are a conjugate of each other, not a and b. This is not intuitive at all.
Also the word 'commutator' and 'conjugate' is in different word class. (conjugator seems better?)
To be clear, in group theory, [a,b] is called a commuatator of a and b. And, a and b form some kind of relationship.
But [a:b], which is b^a, is NOT called a conjugate of a and b. It is called a conjugate of b by a. And, a and b do NOT form some kind of relationship.
So if we want to call [a:b] something, we need a term for this: [a,b] is called a (_________) of a and b.
The problem is the terms 'commutator' and 'conjugator' are not symmetric.
Any suggestions?